div {
  box-sizing: border-box;
}

body,
dl,
dd,
dt,
ol,
ul,
li,
h1,
h2,
h3,
h4,
h5,
h6,
p {
  margin: 0;
}

img {
  /* 去除图片下方空隙，可以换成vertical-align: middle; 或 font-size: 0; */
  vertical-align: middle;
}

a {
  text-decoration: none;
}

ul,
ol,
li {
  list-style: none;
  padding: 0;
}

input {
  outline: none;
}

button {
  border: none;
  outline: none;
}

.clearfix::after {
  content: '';
  display: block;
  clear: both;
}

.fl {
  float: left;
}

.fr {
  float: right;
}

/* 字体，大小和颜色 */
:root {
  font: 16px/1.5 'Helvetica Neue', Helvetica, Arial, sans-serif;
}
